The two photos above show what appears to be the dam of the Thwing mill on the left. They show the upstream side of the dam, west of the river. On the right side of each picture is what was the bottom of the millpond.

This picture shows the top of the dam, also west of the river.

This photo shows the top of the dam, west of the Mill River, taken from the remains of the dam on the east side.

Here's another view of the dam, looking toward the west side of the river.

It seems likely that the stones in the middle of this picture, beyond the river, must have been part a mill building foundation. However, it is on the opposite side of the river from the mill site in the 1851 map below. The 1898 map shows two buildings at the site. The stones may be part of the smaller one.

The map above was drawn in 1851. The complete map can be seen on the wall of the reference room at the Bancroft Library. The Gaskill mills at the bottom right eventually became the Westcott Mill. The saw mill in the middle became the Thwing mill. Considering the millstones that were found on the site, it appears that the mill was converted to a gristmill. Also, as you'll see below, Gordon Hopper referred to it as a gristmill.

This 1898 map shows the Thwing mill near the bottom. The road off of Hopedale Street, between the Hopedale Stable and the John A. Moore properties, appears to be located where Thwing Street is now. The long-gone millpond, extended up to what was called Main Street - now Route 16/Mendon Street.

The Almon Thwing Mill

What I'm referring to as the Thwing mill was probably the one built and operated by Samuel Walker before Almon Thwing took it over. According to Hopper's history of the Mill River, "Samuel Walker’s gristmill with a 9-foot fall occupied the eighth site." He describes it as being downstream from the Dutcher Company site and upstream from the Westcott mill. Evidence that it, at some point, came under the ownership of Almon Thwing is given in Adin Ballou's History of Milford, p. 333. "Thwing St., from Hopedale, westward over Mill River, to gristmill; accepted, 1859; named with respectful reference to Almon Thwing, who then owned the mill-seat; 46 rods, 20 links long, and 2 rods wide; contents, about 93 1/2 rods."As part of his History of Milford, Ballou hired Thwing to survey the town, which at that time (evidently scheduled to be published in time for the Milford Centennial in 1880, but actually printed in 1882) included Hopedale. (The elevations and drops cited in the Hopper history of the Mill River - link below- evidently were taken from Thwing's survey.) Here Ballou refers to the mill near Thwing Steet as belonging to Thwing, but in Thwing's survey of the Mill River, in the same book, he refers to it as Walker's mill. Possibly Thwing owned the land and "mill privilege" but Walker owned the mill. Another possibility is that ownership changed hands during the years when Ballou was working on the book.You may also have noticed that the 1851 map refers to it as a saw mill, but the Hopper history mentions Walker's gristmill. Was one source wrong, or did the function of the mill change? The fact that two millstones were found in the vicinity (see Town Park Millstones below) suggests that it must have been, at least at one time, a gristmill. Possibly it began as a sawmill but over the years the cutting of trees eventually left the area with too few to make it profitable in that line of work and it was converted. Another possibility is that both were there, at the same time.